极坐标点图

极坐标点图 是由 PolarPointSeriesView 对象来表示的，此对象属于极坐标系列视图。当需要以角度为基础把来自两个或多个不同系列中的点在相同的圆形图象上显示时，这种视图是有用的。注意，尽管这些图表通常都有一个圆形形状，但是也可以被显示为多边形。这是通过 RadarDiagram.DrawingStyle 属性进行控制的。

在下面的插图中显示了一个极坐标点图。

下表列出了这种图表类型的主要特征。

特征	取值
系列视图类型	PolarPointSeriesView
图象类型	PolarDiagram
每个数据点的参数个数	1
每个数据点的取值个数	1

注意
要获得关于哪些图表类型可以与极坐标点图组合使用的信息，请参阅组合使用不同的系列视图文档。

下面的示例演示了在运行时刻如何创建 ChartControl (拥有一个 PolarPointSeriesView 类型的系列)，设置它的常规属性，并把图表添加到窗体中。在继续本示例之前，首先要在 Visual Studio 中创建一个 Windows 窗体应用程序，并把所有必需的程序集包含到项目的“引用”列表中。

然后，把下列代码添加到 Form.Load 事件处理程序。

C#	复制代码
using System; using System.Windows.Forms; using DevExpress.XtraCharts; // ... private void Form1_Load(object sender, EventArgs e) { // Create a new chart. ChartControl polarPointChart = new ChartControl(); // Add a polar series to it. Series series1 = new Series("Series 1", ViewType.PolarPoint); // Populate the series with points. series1.Points.Add(new SeriesPoint(0, 90)); series1.Points.Add(new SeriesPoint(45, 70)); series1.Points.Add(new SeriesPoint(90, 50)); series1.Points.Add(new SeriesPoint(135, 100)); series1.Points.Add(new SeriesPoint(180, 90)); series1.Points.Add(new SeriesPoint(225, 70)); series1.Points.Add(new SeriesPoint(270, 50)); // Add the series to the chart. polarPointChart.Series.Add(series1); // Hide the series labels. series1.Label.Visible = false; // Adjust the view-type specific properties of the series. PolarPointSeriesView myView = (PolarPointSeriesView)series1.View; myView.PointMarkerOptions.Kind = MarkerKind.Star; myView.PointMarkerOptions.StarPointCount = 5; myView.PointMarkerOptions.Size = 20; // Flip the diagram (if necessary). ((PolarDiagram)polarPointChart.Diagram).StartAngleInDegrees = 180; ((PolarDiagram)polarPointChart.Diagram).RotationDirection = RadarDiagramRotationDirection.Counterclockwise; // Add a title to the chart, and hide the legend. polarPointChart.Titles.Add(new ChartTitle()); polarPointChart.Titles[0].Text = "A Polar Point Chart"; polarPointChart.Legend.Visible = false; // Add the chart to the form. polarPointChart.Dock = DockStyle.Fill; this.Controls.Add(polarPointChart); }

C#

复制代码

using System;
using System.Windows.Forms;
using DevExpress.XtraCharts;
// ...

private void Form1_Load(object sender, EventArgs e) {
    // Create a new chart.
    ChartControl polarPointChart = new ChartControl();

    // Add a polar series to it.
    Series series1 = new Series("Series 1", ViewType.PolarPoint);

    // Populate the series with points.
    series1.Points.Add(new SeriesPoint(0, 90));
    series1.Points.Add(new SeriesPoint(45, 70));
    series1.Points.Add(new SeriesPoint(90, 50));
    series1.Points.Add(new SeriesPoint(135, 100));
    series1.Points.Add(new SeriesPoint(180, 90));
    series1.Points.Add(new SeriesPoint(225, 70));
    series1.Points.Add(new SeriesPoint(270, 50));

    // Add the series to the chart.
    polarPointChart.Series.Add(series1);

    // Hide the series labels.
    series1.Label.Visible = false;

    // Adjust the view-type specific properties of the series.
    PolarPointSeriesView myView = (PolarPointSeriesView)series1.View;

    myView.PointMarkerOptions.Kind = MarkerKind.Star;
    myView.PointMarkerOptions.StarPointCount = 5;
    myView.PointMarkerOptions.Size = 20;

    // Flip the diagram (if necessary).
    ((PolarDiagram)polarPointChart.Diagram).StartAngleInDegrees = 180;
    ((PolarDiagram)polarPointChart.Diagram).RotationDirection =
        RadarDiagramRotationDirection.Counterclockwise;

    // Add a title to the chart, and hide the legend.
    polarPointChart.Titles.Add(new ChartTitle());
    polarPointChart.Titles[0].Text = "A Polar Point Chart";
    polarPointChart.Legend.Visible = false;

    // Add the chart to the form.
    polarPointChart.Dock = DockStyle.Fill;
    this.Controls.Add(polarPointChart);
}

Visual Basic	复制代码
Imports System Imports System.Windows.Forms Imports DevExpress.XtraCharts ' ... Private Sub Form1_Load(ByVal sender As Object, ByVal e As EventArgs) _ Handles MyBase.Load ' Create a new chart. Dim polarPointChart As New ChartControl() ' Add a polar series to it. Dim series1 As New Series("Series 1", ViewType.PolarPoint) ' Populate the series with points. series1.Points.Add(New SeriesPoint(0, 90)) series1.Points.Add(New SeriesPoint(45, 70)) series1.Points.Add(New SeriesPoint(90, 50)) series1.Points.Add(New SeriesPoint(135, 100)) series1.Points.Add(New SeriesPoint(180, 90)) series1.Points.Add(New SeriesPoint(225, 70)) series1.Points.Add(New SeriesPoint(270, 50)) ' Add the series to the chart. polarPointChart.Series.Add(series1) ' Hide the series labels. series1.Label.Visible = False ' Adjust the view-type specific properties of the series. Dim myView As PolarPointSeriesView = CType(series1.View, PolarPointSeriesView) myView.PointMarkerOptions.Kind = MarkerKind.Star myView.PointMarkerOptions.StarPointCount = 5 myView.PointMarkerOptions.Size = 20 ' Flip the diagram (if necessary). CType(polarPointChart.Diagram, PolarDiagram).StartAngleInDegrees = 180 CType(polarPointChart.Diagram, PolarDiagram).RotationDirection = _ RadarDiagramRotationDirection.Counterclockwise ' Add a title to the chart, and hide the legend. polarPointChart.Titles.Add(New ChartTitle()) polarPointChart.Titles(0).Text = "A Polar Point Chart" polarPointChart.Legend.Visible = False ' Add the chart to the form. polarPointChart.Dock = DockStyle.Fill Me.Controls.Add(polarPointChart) End Sub

Visual Basic

复制代码

Imports System
Imports System.Windows.Forms
Imports DevExpress.XtraCharts
' ...

Private Sub Form1_Load(ByVal sender As Object, ByVal e As EventArgs) _ 
Handles MyBase.Load
    ' Create a new chart.
    Dim polarPointChart As New ChartControl()

    ' Add a polar series to it.
    Dim series1 As New Series("Series 1", ViewType.PolarPoint)

    ' Populate the series with points.
    series1.Points.Add(New SeriesPoint(0, 90))
    series1.Points.Add(New SeriesPoint(45, 70))
    series1.Points.Add(New SeriesPoint(90, 50))
    series1.Points.Add(New SeriesPoint(135, 100))
    series1.Points.Add(New SeriesPoint(180, 90))
    series1.Points.Add(New SeriesPoint(225, 70))
    series1.Points.Add(New SeriesPoint(270, 50))

    ' Add the series to the chart.
    polarPointChart.Series.Add(series1)

    ' Hide the series labels.
    series1.Label.Visible = False

    ' Adjust the view-type specific properties of the series.
    Dim myView As PolarPointSeriesView = CType(series1.View, PolarPointSeriesView)

    myView.PointMarkerOptions.Kind = MarkerKind.Star
    myView.PointMarkerOptions.StarPointCount = 5
    myView.PointMarkerOptions.Size = 20

    ' Flip the diagram (if necessary).
    CType(polarPointChart.Diagram, PolarDiagram).StartAngleInDegrees = 180
    CType(polarPointChart.Diagram, PolarDiagram).RotationDirection = _ 
        RadarDiagramRotationDirection.Counterclockwise

    ' Add a title to the chart, and hide the legend.
    polarPointChart.Titles.Add(New ChartTitle())
    polarPointChart.Titles(0).Text = "A Polar Point Chart"
    polarPointChart.Legend.Visible = False

    ' Add the chart to the form.
    polarPointChart.Dock = DockStyle.Fill
    Me.Controls.Add(polarPointChart)
End Sub

Show Me
在 DevExpress Code Central 数据库中可以找到完整的示例项目，网址是 http://www.devexpress.com/example=E1057。取决于目标平台类型 (ASP.NET、WinForms 等)，可以在线运行本示例，或者下载自动可执行的示例。

雷达图象和极坐标图象

简要说明

图表类型特征

示例

参阅